1. Field of the Invention
The invention relates to a map indication device and to a navigation device which produces route guidance to a destination (goal) that is set by a user.
2. Description of the Related Art
A conventional map indication device can be represented by, for example, a car navigation device mounted on a car. The car navigation device stores a plurality of items related to places, such as geographical names, telephone numbers and addresses of buildings, parks, companies. These items have been stored in the navigation device together with representative coordinates that specify the geographical location of each facility. When an item, such as the geographical name, telephone number, or address is specified by the user, the destination desired by the user is thereby input to the navigation device. According to another navigation device, a particular point can be designated on a map presented on a display using a cursor. In such a navigation device, when a point, which is the destination, is designated by the user on the map picture using the cursor, the coordinates of the designated point are set to the navigation device as a destination point.
As described above, designating the destination using the means described above makes it convenient to reliably select the destination. However, the above-mentioned navigation devices require list data in which geographical coordinates of destination points are corresponded to the items, such as geographical names, telephone numbers, and addresses, that are related to a plurality of possible destination points on a map. Such list data must be stored in a memory having a very large capacity. The navigation device equipped with the memory having such a very large capacity results in an increase in the cost of production.
Therefore, the conventional navigation devices have been provided with a memory of limited capacity to avoid an increase in the cost of production. That is, the list data stored in the navigation device consists only of that data associated with major places. In other words, the navigation device does not store list data related to all possible places.
Therefore, when geographic places, that are not included in the list data, are to be set as destinations, such destinations must be designated by a separate method such as the one in which a map picture of a region including the destination is indicated on the display of the navigation device, and the destination is designated by using a cursor on the map picture displayed. It is, however, difficult to move the cursor to an exact point on the map picture.
In the conventional navigation device, furthermore, setting the destinations and detecting the present position of the car are effected by using a road map based upon road data. Besides, searching the route up to a designated destination from the present position of the car and road guidance along the searched route are performed using the road map.
In order to offer proper route guidance while the car is running, the map on the display of the navigation device indicates only a minimum of data. This is to easily allow the driver, or user, to know the present position of the car and the principal roads along which he/she may proceed.
As described above, the conventional navigation device indicates small amounts of data and, hence, offers relatively small amounts of data from which the user must confirm the destination or a particular facility desired by the user. Accordingly, the user may often find it cumbersome to determine the exact point. With the map data consisting of conventional road data, the user may overlook the destination on the displayed map despite the fact the user is approaching the destination according to the route guidance. As a result, the user passes by the destination and must take a detour to arrive at the destination; i.e., the function of the navigation device is often not efficiently used.
In the conventional navigation device, the roads on the map indicated on the picture generally consist of straight lines coupling a plurality of coordinate points. Besides, large facilities are surrounded by lines so that the entire site of the facilities can be observed. Further, names of the facilities are often indicated on the map picture. When map coordinates are input for setting the destination, there may often be searched a road in the vicinity of the coordinates or an intersection closest to the coordinates. The point or the intersection on the searched road is set as an end point of the route guidance, and a route is searched from the present position of the car to the end point.
With the facilities being surrounded by lines as described above, however, it is not often obvious on the picture where the entrance to the facility is located. Moreover, since the end point of the route guidance is set and the guide route is searched based on the input point, the route is guided to the vicinity of the destination. When the surrounding of the facility at the destination has a complex shape, however, the user is often finally guided to the back door or to a byroad of the facility at the destination if the principal entrance is not known by the user.